A man accused of being one of world's most notorious wildlife traffickers has been arrested in Thailand.

Boonchai Bach, 40, is alleged to have made a career out of helping to smuggle thousands of tonnes of rhino horns and elephant tusks from Africa to Asia.

But he was arrested by police at his base in Nakorn Panom, Thailand, next to the Mekong River, on Friday.

Bach, a Vietnamese national with Thai citizenship, is being held in relation to the trafficking of 14 rhino horns in December.

Authorities said they are also investigating allegations he supervised groups trafficking large quantities of poached elephant ivory, rhino horns, pangolins, tigers, lions, and other rare and endangered species for more than a decade.

At a news conference at Bangkok's Suvarnabhumi Airport, Police Colonel Chutrakul Yodmadee told reporters that the arrest was "significant for many reasons".

"The confiscated items are high in value.

"And we are able to arrest the whole network involved, starting from the courier, the facilitator, the exporter who plan to export goods through the Thai-Laos border.

"We even got the moneyman (investor) behind the gang.

"That means we are able to arrest the whole network."

Image:After his arrest, Bach is fingerprinted by Thai police in Bangkok

The Bach family is alleged to have run the international supply chain of illicit wildlife from Asia and Africa to major dealers in Laos, Vietnam and China, including to the notorious Vixay Keosavang.

Keosavang, based in Laos, was named Southeast Asia's biggest wildlife dealer by the New York Times in 2013.

It is claimed Boonchai Bach took up a leading role in the organisation in 2005 when he began to share power with his brother.

Freeland, a Bangkok-based anti-trafficking organisation, has been working with Thai authorities on the investigation after tracking the group for more than two decades.

He added: "The security officers of Suvarnabhumi Airport, Suvarnabhumi Airport Police Station, Thai Customs and Immigration Police at Nakhon Panom are to be congratulated for breaking open the country's largest wildlife crime case ever."

Image:Bach, 40, is a Vietnamese national with Thai citizenship

This week's arrest follows the routine X-ray of cargo on a flight from Ethiopia to Bangkok in December which revealed rhino horns hidden in a suitcase.

Officials let the luggage through and then followed it to a Thai officer in the airport who was arrested along with one of Bach's relatives.

Bach was once believed to be untouchable, and campaigners hope his arrest will encourage crackdowns around the world.